Drilling the Exhaust Manifold....SCARED

[dmbrichie]

Just wondering if I need a special drill bit to drill into the manifold for the sensor??? I see in the instructions it says to use a "size R" Tap or 1/8" Tap.. Not really sure if that is a special drill bit or can I just use a 1/8" metal drill bit??? I am thinking that once the hole is drilled in that the threads on the sensor will just thread itself into the metal, is that right??? Thanks guys...

[Raul@Stealth Automotive]

you can use whatever drill bit to drill the whole... but you will need a Tap to make the threads..... i believe its a 1/8th NPT pipe thread... i could be wrong... i know we had to buy one when we were installing a probe on Nicks truck..... i found it at a plumbers supply place... take your sensor to someplace like this and they will get you squared away

[vitalidle]

No use a size R" drill bit (0.339") and then use a 1/8" NPT. You need to tap the hole don't try to self thread with the thermocouple

[Raul@Stealth Automotive]

Originally Posted by vitalidle

No use a size R" drill bit (0.339") and then use a 1/8" NPT. You need to tap the hole don't try to self thread with the thermocouple

what he said lol.....

[vitalidle]

Also just another good idea is to use some high temp anti sieze on the thermocouple threads before you install just in case your thermocouple goes bad down the road you can get it back out to replace with a new one

[dmbrichie]

thanks a lot guys...

[tech10002]

The drill bit my tap took was a 21/64" . The tap will be marked with what size drill you need. But don't start out with that one. Start with a very small bit and keep going bigger and bigger until you get to the final size. That will keep the shavings small and greatly reduce the risk of breaking off a bit in the manifold.

I got my tap at Ace hardware. It's a 1/8-27 or 1/8 NPT. They are one in the same. It's a lot easier to just use an open end wrench to turn the tap. There's not really enough room in there to get a tap handle. Just tap a little at a time, and back out every couple turns to clear the shavings. Make sure your tap is well lubricated with some kind of oil. If you take it slow, you will have no problems.

These are the instructions pretty much everyone refers to for installing the probe: 3-Gauge Install Pictures

[ShawnCT450R]

My machinist at work told me to use an 11/32 drill bit prior to tapping the 1/8" hole. Worked perfectly. Took a long time because I took my time and cleaned it out a few times. Drilled to hole in 5 steps, small to large, and ended up at 11/32. Find the long tap driver wrench or whatever it's called. Trying to get the tap started with a little wrench sucks. Good luck.